THE IMPACT OF STRESS ON AUTONOMIC

FUNCTIONING IN CHRONIC ABDOMINAL

PAIN PATIENTS

Davlyn M. Tillman

Under the Direction of Dr. Lynn Walker  

INTRODUCTIONThe main topic of this study was Chronic Abdominal

Pain. Chronic abdominal pain (CAP) is a recurring pain in the abdomen common in childhood. The criteria are three or more episodes of abdominal pain that occur over at least three months and affect normal daily activities (Apley, 1975).

This study specifically focused on the physiological and psychological Impact of Stress on participants with Chronic Abdominal Pain Specific Effects on Autonomic Functioning – Increases

in Blood Pressure Specific Effects on Positive and Negative Affect –

Decreases in Positive Affect and Increases in Negative Affect

Goal of Study Non-recovered and recovered CAP patients and well

controls were subjected to a laboratory social stressor to measure physiological and psychological responses

Hypotheses Tested Non-recovered CAP patients will

experience greater physiological change in blood pressure levels in relation to recovered CAP Patients and well controls

Non-recovered CAP patients will experience lower positive affect and higher negative affect in relation to recovered CAP Patients and well controls

METHODS Participants

317 recovered and non-recovered CAP patients and control (“well”) participants from the Middle Tennessee area

Currently between ages 13-32 Measures

Health Interview (Rome III) Used to determine whether recovered or non-recovered CAP

Social Competence Interview Laboratory Stressor – in-depth discussion of work, school, friend,

neighborhood, money, or family stress Physiological Assessment

Blood Pressure measurements taken during baseline and SCI Symptom Emotion Report (SER)

Questionnaire to measure positive and negative affect

Procedure Participants complete 45-60 minute health interview

by phone Questions on subjects such as demographics,

behavior, and physical wellness Participants then come into research lab at

Children’s Hospital to complete the lab session and social stressor: Baseline blood pressure measurements during

landscape slideshowSER1 SurveySocial Competence Interview (active and cool

phase) – participants discuss chosen social stressor with interviewer

SER2 SurveyRecovery period blood pressure measurements

during slideshow

RESULTS Demographics:

317 participants in the study Mean age of 20.34 years, S.D. = 4.37 Participants were 59.6% female and 40.4% male 93 well participants, 143 recovered CAP

participants, and 81 non-recovered participants 92.7 Caucasian

RESULTS: BLOOD PRESSURE MEASUREMENTS

Mean of baseline blood pressures were subtracted from mean of two maximum blood pressures

UNIANOVA statistical test All three groups experienced increase in BP due

to laboratory stressor No significant difference between groups in

systolic and diastolic blood pressure changesSystolic: p<0.47Diastolic: p<0.08

RESULTS: BLOOD PRESSURE MEASUREMENTS

Baseline SCI Active Maximum BP in SCI Active 0.00

20.00

40.00

60.00

80.00

100.00

120.00

140.00Changes in Systolic and Diastolic BP

Unrecovered CAP: Systolic Unrecovered CAP: Diastolic Recovered CAP: SystolicRecovered CAP: Diastolic Well: Systolic Well: Diastolic

Experiment Phases Systo

lic

and D

iasto

lic

BP

Means

(mm

HG

)

RESULTS: POSITIVE AND NEGATIVE AFFECT

Mean score for Time 1 subtracted from mean scores for Time 2 Calculated for both positive and negative affect

One way ANOVA statistical test All three groups experienced a decrease in positive

affect and increase in negative affect in response to laboratory stressor

No significant difference between groups in positive and negative affect changes Positive affect: p<0.052 Negative affect: p<0.605

RESULTS: POSITIVE AFFECT

Positive Affect Time 1 (SER PA mean score)

Positive Affect Time 2 (SER PA mean score)

1.0000

2.0000

3.0000

4.0000

Wells

Resolved CAP

Unresolved CAP

RESULTS: NEGATIVE AFFECT

Negative Affect Time 1 (SER NA mean score)

Negative Affect Time 2 (SER NA mean score)

1.0000

2.0000

3.0000

4.0000

5.0000

WellsResolved CAPUnresolved CAP

CONCLUSION Key Findings

The expected changes in blood pressure, positive affect, and negative affect were similar in all three sub-groups

There were no significant differences in changes for non-recovered CAP participants

Potential Implications All three groups seem to have similar biological responses to social stressor The groups may instead have different perceptions of stress that cause

differences in self-report of somatic symptoms Positive and Negative Affect results have implications for further studies on coping

strategies in patients with chronic abdominal pain patients Limitations

The exact stressor discussed during the interview differed for each participants Measurements of positive and negative affect were self-reports The SCI was a short-term stressor and different results may be seen for a chronic

stressor Future Direction

Studies focusing on the cognitive effects of stress on chronic abdominal pain patients such as differences in perception as opposed to the physiological effects such as blood pressure

Prospective studies that test types of coping strategies and success of strategies used by those who have recovered from chronic abdominal pain

ACKNOWLEDGEMENTS

Dr. Lynn Walker, Walker Lab, Vanderbilt Children’s Hospital

Grace Shelby, Graduate Student,Walker Lab Dr. Craig Smith, Honors Program Director